ES2341151T3 - IRON-NICKEL-CHROME-SILICON ALLOY. - Google Patents

Abstract

Iron-nickel-chromium-silicon alloy having (in % by weight) 34 to 42% nickel, 18 to 26% chromium, 1.0 to 2.5% silicon, and additives of 0.05 to 1% Al, 0.01 to 1% Mn, 0.01 to 0.26% lanthanum, 0.0005 to 0.05% magnesium, 0.01 to 0.14% carbon, 0.01 to 0.14% nitrogen, max. 0.01% sulfur, max. 0.005% B, remainder iron and the usual impurities resulting from the production process.

Description

Alloy iron-nickel-chromium-silicon.

The invention relates to an alloy of iron-nickel-chromium-silicon with improved life and dimensional stability.

The alloys of iron-nickel-chromium-silicon austenitic with different nickel, chromium and silicon contents have long been used as heating conductors in the temperature range up to 1100 ° C. This group of alloys It is standardized in DIN 17470 (Table 1) and ASTM B344-83 (Table 2) for use as an alloy for heating conductors For this standard there is a series of commercially available alloys listed in the Table 3.

The sharp rise in the price of nickel in the In recent years, the desire to use alloys for heating conductors with nickel contents if possible low. In this regard there is especially the desire to replace variants with high nickel content NiCr8020, NiCr7030 and NiCr6015 (Table 1), which stand out for properties especially advantageous, for materials with reduced nickel content without must accept too large losses in the performance of materials.

In general it should be noted that the shelf life and operating temperature of the alloys specified in the Tables 1 and 2 increase with increasing nickel content. All these Alloys form a layer of chromium oxide (Cr 2 O 3) with a layer of SiO_ {2} more or less closed below. Small additions of elements strongly related to oxygen such as Ce, Zr, Th, Ca, Ta (Pfeifer / Thomas, Zunderfeste Legierungen, 2nd edition, Springer Verlag 1963, pages 258 and 259) raise lives useful investigating in the cited case only the influence of a only element related to oxygen, but not providing information on the action of a combination of elements of this type. He Chrome content is consumed slowly over the course of the use of a heating conductor for the construction of the protective layer For this reason, the service life is increased by a higher chromium content since a higher element content chrome that forms the protective layer delays the moment when the Cr content is below the critical limit and are formed oxides other than Cr 2 O 3 which are, for example, oxides that They contain iron.

By document EP = A 0 531 775 it has been given to know a thermally moldable austenitic nickel alloy Heat resistant of the following composition (in% by weight):

one

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EP A 0 386 730 describes a nickel-chrome-iron alloy with very good oxidation resistance and heat resistance as wish for advanced heating conductor applications which are based on the well-known alloy for conductors of NiCr6015 heating and in which by modifications adjusted to each other of the composition could be achieved specifically considerable improvements of use properties. The alloy differs from the known material NiCr6015 especially in which rare earth metals are replaced by yttrium that additionally it contains zirconium and titanium, and in that the content of  nitrogen is specially adjusted to zirconium contents and titanium

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From WO-A 2005/031018 an austenitic alloy of Fe-Cr-Ni for use in the high temperature range that essentially presents the following chemical composition (in% by weight):

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In heating elements freely There is also a requirement, in addition to the requirement of high service life, good dimensional stability at application temperature A sagging too strong of the filament during operation results in a uneven separation of the turns with a distribution of uneven temperature, so the service life is shortened. For compensate for this would require more footholds for the heating filament, which increases costs. That is to say, that the material for heating conductors must have a dimensional stability or creep resistance sufficiently good.

All creep mechanisms that harm dimensional stability in the temperature range of application (displacement creep, granular boundary migration or diffusion creep) are influenced, except creep dislocation, by a large grain size in the direction of greatest Creep resistance. Displacement creep does not depend Grain size The production of a wire with large size of grain increases creep resistance and therefore the dimensional stability. For this reason, in all considerations should also be considered grain size as An important influence factor.

In addition, for a material for conductors of heating is important a specific electrical resistance to be possible high and a change if possible small of the relationship heat resistance / cold resistance with temperature (temperature coefficient ct).

Variations with lower nickel content NiCr3020 or 35Ni, 20Cr (Table 1 or Table 2) that stand out for costs clearly lower meet only insufficiently especially The requirements of the useful life.

Therefore, the objective is to design a alloy that with nickel content clearly lower than NiCr6015 and, therefore, considerably lower costs have

to)

high oxidation resistance and long life useful associated with it

b)

dimensional stability good enough to application temperature

C)

a high specific electrical resistance along with a change if possible under the resistance to heat / cold resistance with temperature (coefficient of ct temperature).

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This objective is achieved by an alloy from iron-nickel-chromium-silicon with (in% by weight) 34 to 42% nickel, 18 to 26% chromium, 1.0 to 2.5% silicon and additions of 0.05 to 1% of Al, 0.01 to 1% of Mn, 0.01 to 0.26% lanthanum, 0.0005 to 0.05% magnesium, 0.01 to 0.14% carbon, 0.01 to 0.14% nitrogen, max. 0.01% sulfur, max. 0.005% B, the rest iron and the usual impurities inherent to the procedure

Advantageous variants of the object of the invention are extracted from the dependent claims corresponding.

Due to its special composition, this alloy It has a longer lifespan than alloys according to the state of the technique with the same nickel and chromium contents. Additionally, high stability can be achieved. dimensional or less combined than alloys according to the state of the technique with 0.04 to 0.10% carbon.

The dispersion interval for the element Nickel is between 34 and 42% and may occur depending on of the use case nickel contents such as following:

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34-39%

-

34-38%

-

34-37%

-

37-38%

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The chromium content is between 18 and 26% can also be given here, depending on the area of use of the alloy, chromium contents such as following:

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20-24%

-

21-24%

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The silicon content is among the 1.0 and 2.5% can be adjusted depending on the area of application defined contents within the dispersion range:

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1.5-2.5%

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1.0-1.5%

-

1.5-2.0%

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1.7-2.5%

-

1.2-1.7%

-

1.7-2.2%

-

2.0-2.5%

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The aluminum element is intended as an addition and specifically in contents of 0.05 to 1%. Preferably, It can also be adjusted as follows in the alloy:

-

0.1-0.7%

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The same applies to the manganese element that is add 0.01 to 1% of the alloy. Alternatively also The following dispersion interval would be possible:

-

0.1-0.7%

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The object of the invention is based preferably in that the properties of specified materials in the examples they fit essentially with the addition of lanthanum element in contents of 0.01 to 0.26%. Depending on application area, defined values can also be set here in the alloy:

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0.01-0.2%

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0.02-0.15%

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0.04-0.15%.

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This applies equally to the element. nitrogen that is added in contents between 0.01 and 0.14%. Defined contents can be given as follows:

-

0.02-0.10%

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0.03-0.09%.

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Carbon is added in the same way to the alloy, and specifically in contents between 0.01 and 0.14%. Specifically, contents can be adjusted as follows in the alloy:

-

0.04-0.14%

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0.04-0.10%.

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Magnesium is also among the elements of addition in contents of 0.0005 to 0.05%. Specifically there the possibility of adjusting this element as follows in the alloy:

-

0.001-0.05%

-

0.008-0.05%.

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Sulfur and boron elements can occur in the alloy as follows:

Sulfur

max. 0.01%, preferably max. 0.005%

Boron

max. 0.005%, preferably max. 0.003%

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The alloy may also contain calcium in contents between 0.0005 and 0.07%, especially 0.001 to 0.05% or 0.01 to 0.05%.

If the effectiveness of the lanthanum reactive element alone is not enough to produce material properties exposed in the objective approach, the alloy can also contain at least one of the elements Ce, Y, Zr, Hf, Ti with a content of 0.01 to 0.3%, which can also temporarily be Defined additions

Additives of oxygen-related elements such as La, Ce, Y, Zr, Hf, Ti improve the shelf life. They do this joining the oxide layer and blocking there in the limits granular oxygen diffusion pathways. For this reason, the number of elements that are available for this mechanism must be normalized to atomic weight to be able to compare quantities of different elements with each other.

For this reason, the potential of elements assets (PwE) is defined as

PwE = 200 \ cdot \ Sigma (X_ {/ atomic weight of AND)

in which E is the element in question and X_ {E} the content of the element in question in percentage.

As already mentioned, the alloy can contain from 0.01 to 0.3% respectively of one or more of the elements La, Ce, Y, Zr, Hf, Ti, being

\ Sigma PwE = 1.43 \ X_ {Ce} + 1.49 \ X_ {La} + 2.25 \ X_ {Y} + 2.19 \ X_ {Zr} + 1.12 X_ {Hf} + 4.18 \ X_ {Ti} \ leq 0.38,

especially ≤ 0.36 (a of 0.01 to 0.2% of total element), PwE corresponding to the potential of The elements assets.

Alternatively, in case at least one of The elements La, Ce, Y, Zr, Hf, Ti are present in the contents of the 0.02 to 0.10% there is a possibility that the sum PwE = 1.43 X_ {Ce} + 1.49 \ x X {La} + 2.25 X_ {Y} + 2.19 \ cdot X_ {Zr} + 1.12 X_ {Hf} + 4.18 \ X_ {Ti} is less than or equal to 0.36, PwE corresponding to the potential of the elements assets.

The alloy may also have a content phosphorus between 0.001 and 0.020%, especially 0.005 to 0.020%

In addition, the alloy may contain between 0.01 and 1.0% respectively of one or more of the elements Mo, W, V, Nb, Ta, Co which also can still be limited from the following mode:

-

0.01 at 0.2%

-

0.01 at 0.06%.

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Finally, the elements copper, lead, zinc and tin can still occur in impurities in contents of the following mode:

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The alloy according to the invention should be used for use in electric heating elements, especially in electric heating elements that require high dimensional stability and low bending.

A case of concrete application of the alloy according to the invention is the use in the construction of ovens

The object of the invention is explained more. in detail by the following examples.

Examples

Tables 1 to 3 reproduce - as already stated mentioned at the beginning - the state of the art.

Alloys are shown in Tables 4a and 4b from iron-nickel-chromium-silicon melted on an industrial scale according to the state of the art T1 to T7, a molten alloy on a laboratory scale according to the state of the T8 technique and various experimental alloys according to the invention fused to laboratory scale V771 to V777, V1070 to V1076, V1090 to V1093 for the optimization of alloy composition.

In the case of scale cast alloys of laboratory T8, V771-V777, V1070-V1076, V1090 - V1093, from material block casting a soft annealed wire was prepared with a 1.29 mm diameter by hot rolling, cold drawn and appropriate intermediate or final anneals.

In the case of scale cast alloys industrial T1-T7, of scale manufacturing industrial sample was taken industrially finished and with Soft annealed with a diameter of 1.29 mm. For the essay of the shelf life a smaller partial amount of wire was taken respectively at a laboratory scale of up to 0.4 mm.

For the heating conductor in the form of wire are possible and usual accelerated life tests to compare the materials with each other, for example, with the following conditions:

The life test of drivers of heating is done on wires with a diameter of 0.40 mm. He wire is tensioned between 2 power supplies at the distance of 150 mm and is heated by applying a tension of up to 1150 ° C. Heating to 1150 ° C is performed respectively. for 2 minutes, then the power supply is interrupted for 15 seconds At the end of the service life, the wire fails because the remaining cross section melts. The time of combustion is the sum of the "ignition" times during the wire life. The relative combustion time tb is the % data referring to the burning time of a batch of reference.

To investigate dimensional stability, in a combing test investigates the fall behavior (warped) of the heating filament at the temperature of application. In this regard, in heating filaments records the combating of the horizontal filaments after a set time The smaller the combado, the greater the dimensional stability or creep resistance of material.

For this experiment, wire with annealing soft with a diameter of 1.29 mm is wound in spirals with a internal diameter of 14 mm. In total, for each batch 6 are manufactured heating filaments with respectively 31 turns. Everybody the heating filaments are regulated at the beginning of the experiment at a uniform initial temperature of 1000 ° C. The temperature is Determine with a pyrometer. The experiment is performed with a cycle 30 s connection "on" / 30 s "off" on voltage constant. The experiment ends after 4 hours. After of the heating filament cooling, the combating of the individual turns are measured from the horizontal and form the average value of 6 values. These values (mm) are introduced in Table 4b.

Examples of the following are listed in Table 4a and 4b. alloys according to the state of the art T1 to T7. T1 and T2 are alloys with approximately 30% nickel, approximately 20% of Cr and approximately 2% Si. They contain rare earth additions (SE), in this case mixed cerium metal which means that the SE is consisting of approximately 60% of Ce, approximately 35% of La and the rest Pr and Nd. The relative burn time amounts to 24% or 35%.

Example T3 is an alloy with approximately 40% nickel, approximately 20% Cr and approximately 1.3% Si. Contains rare earth additions (SE), in this case mixed cerium metal which means that the SE is about 60% of Ce, about 35% of La and the rest Pr and Nd The relative burn time is 72%.

Examples T4 to T7 are alloys with approximately 60% nickel, approximately 16% Cr and approximately 1.2 - 1.5% Si. They contain land additions rare (SE), in this case mixed cerium metal which means that the SE is approximately 60% Ce, approximately 35% La and the rest Pr and Nd. The relative burn time is in the range of about 100 to 130%.

In addition, Tables 4a and 4b contain a series of molten alloys on a laboratory scale. Cast alloy at laboratory scale according to the state of the art T8 is a alloy with 36.2% nickel, 20.8% Cr and 1.87% Si.

Contains, like manufactured alloys on an industrial scale T1-T7, land additions Rare (SE) in the form of cerium mixed metal which means that the SE it's about 60% Ce, about 35% La and the rest Pr and Nd and, apart from the content of Ni, Cr and Si, it was melted according to same specifications as industrial scale lots. By therefore, the batches according to the state of the art T1 to T8 are directly comparable. The relative burn time of T8 amounts to 53%.

In experimental alloys according to invention fused to laboratory scale V771 to V777, V1070 a V1076, V1090 to V1093, the Ni content amounts to approximately 36%, Cr content to approximately 20% and content from Si to approximately 1.8%. Ce additions were varied, The, Y, Zr, Hf, Ti, Al, Ca, Mg C, N. For this reason, these lots can be compared directly with alloys according to the state of the T8 technique which, therefore, serves as a reference alloy for optimization

The addition of Ce and La in V771 to V777, V1070, V1071 and V1076 is done by a mixed metal addition of cerium. For this reason, these lots still contain, in addition to Ce and La, minimum amounts of Pr and Nd but these have not been cited explicitly in Table 4a due to its minimal proportions quantitative

As already mentioned, the additives of oxygen-related elements improve the shelf life. They do this joining the oxide layer and blocking there in the limits granular oxygen diffusion pathways. For this reason, the number of elements that are available for this mechanism must be normalized to atomic weight to be able to compare quantities of different elements with each other.

For this reason, the potential of elements assets (PwE) is defined as

PwE = 200 * sum (X_ {/ atomic weight of AND)

in which E is the element in question and X_ {E} the content of the element in question in percentage.

Fig. 1 shows a graphic representation of the relative burning time tb and the potential PwE for different alloys specified in Tables 4a and 4b. Zone A: usual content of active elements, zone B: possible content of active elements, zone C: too high content of elements assets.

In the comparison of T6 with T7 it attracts attention that the content of SE is the same; however T7 has, despite slightly longer lifespan, smaller Ca content and Mg. In the presence of SE or Ce or La, it seems that Ca and Mg no longer They belong to the active elements. As in the melts of laboratory without SE or Ce or La Ca or Mg is always lower or equal to 0.001%, these two elements are not included in the potential of the active elements.

For this reason, the sum for the potential of PwE active elements has been exposed by Ce, La, Y, Zr, Hf and You. If there is no data for Ce and La, but because of the addition mixed cerium metal only a global SE data is provided, then, for the calculation of PwE, Ce = 0.6 SE and La = 0.35 are assumed BE.

PwE = 1.43 \ X x {Ce} + 1.49 \ X_ {La} + 2.25 \ X_ {Y} + 2.19 X_ {Zr} + 1.12 X_ {Hf} + 4.18 \ cdot For you}

In the case of alloys according to the state of technique T1 to T8, PwE is between 0.11 (T2 and T4) and 0.15 (T6 and T7). The alloy according to the state of the art T8, which at same time is the reference alloy for the melts experimental, has a PwE of 0.12.

Experimental melts V1090 and V1072 in which no mixed cerium metal was added, that is, neither Ce ni La, but Y, show a relative burn time more smaller than T8, although V1090 with 0.10 has a slightly more PwE small, but for this V1072 has with 0.18 a larger PwE. He and it seems that it does not act as well as Ce and / or La, so that a replacement of the SE by Y leads to a worsening in comparison with the state of the art. Through other additions of Zr and Ti (V1074) or Zr and Hf (V1092, V1073, V1091, V1093) in different quantitative proportions have been achieved by New life of T8. But for this, in all cases it was PwE greater than 0.28 required (0.28 for V1092 and V1073; 0.50 for V1074; 0.33 for V1091 and 0.42 for V1093). This increases the costs due to higher consumption of oxygen-related elements expensive and for this reason it is not an advantageous route.

Experimental melts V771 to V777, V1070, V1071 have all been fused with cerium mixed metal, V1075 It only contains La. Of these experimental melts, the masses V1075 and V777 experimental melts reached the longest time of relative combustion of approximately 70%. The PwE of V777 is with 0.36 clearly higher than in V1075 with 0.20, which is in the PwE limit of alloys according to the state of the art. Due to this it is evident that a high amount of elements related to oxygen is not decisive to reach a high combustion time relative, but it is much more important to add related elements to defined oxygen. Burning time reached similarly good relative with V777 with a combination of 0.06% of Ce, 0.02% of La, 0.03% of Zr and 0.04% of Ti. However, for This requires a PwE much larger than 0.36 as in V1075. For V772, the relative burning time is slightly lower than in V1075 and V777 although the same amount of that contained in V1075 The PwE is 0.53 very high. Too high content of oxygen-related elements leads to reinforced internal oxidation and, therefore, in the final effect of a shortening of the time of relative combustion Therefore, it does not seem practical to overcome clearly a PwE of 0.36. V771 has with 0.23 a PwE just something greater than V1075, but a relative burn time clearly smaller. In V771, a large part of the elements related to oxygen are constituted by Ce and only the smallest part by The. Consequently, it seems that La is much more effective as additive that improves combustion time than Ce. Apparently, This also cannot be compensated for by a sharp increase in both Ce 0.17% as 0.08% La as V773 shows with a time of Relative combustion almost equal of 58% at a high PwE of 0.36. This confirms the assertion already made that it is not practical to PwE of clearly greater than 0.36. But even at a PwE of 0.22 as in V776 with a relative burn time of 59%, a combination of Ce = 0.06% and La = 0.02% and Zr = 0.05% seems to be not as effective as adding only La in V1075, which means that Zr is not as effective as La. The same applies to a additional addition of Y to Ce and La as shown by V774 (PwE = 0.28) and a combination of Ce, La, Zr and Hf as shown in V1070 (PwE = 0.19). An increase of PwE from 1.7 times to 0.32 for the combination Ce, La, Zr and Hf only brings an elongation of the relative combustion time of 1.15 times in V1076, which on the other hand shows that PwE Too tall are no longer as effective. This is again evident. in the comparison of V1071 with V777. V1071 has the same content of Ce, La, Zr than V777, only a clearly higher content of You, which means a PwE of 0.44 and a burning time clearly reduced compared to V777 of only 49%. V775 with 0.07% of Ce and 0.03% of La, 0.05% of Y and 0.03% of Hf with a PwE of 0.30 only it has a relative burn time of 46%, which shows that Additional additions of Y and Zr to Ce and La are not as effective.

Figure 2 is a graphic representation of relative combustion times and PwE to clarify the above described Figure 2 shows the relative burning time of T1 to T8 alloys according to the state of the art depending on the nickel content. The lines limit the dispersion band in the relative combustion times in which the alloys according to the state of the art depending on the content of nickel. Additionally the experimental alloy V1075 is marked with the addition of the most effective element. Its useful life is It is clearly above the dispersion band.

Table 4b summarizes the combined with the grain size of the wires. The alloys according to the state of the technique T1 to T8 show a combined between 4.5 and 6.2 mm at sizes of grain comparable between 20 and 25 µm.

Figure 3 shows a representation with respect to nickel content. But it seems that this is not decisive for the cambered.

Figure 4 shows a representation of T1 to T8 alloys and experimental alloys with respect to the C content. Since experimental alloys have different grain sizes, they were classified into 2 classes: grain sizes from 19 to 26 µm and sizes of grain from 11 to 16 µm. Alloys T1 to T8 and experimental alloys with a grain size of 19 µm to 26 µm having comparable grain sizes all show a similar warp in the range of 4.5 to 6.2 mm. Experimental alloys having a grain size of 11 to 16 µm and a carbon content of less than 0.042% show a greater combustion of approximately 8 mm, as expected due to the smaller grain size. Experimental alloys with a grain size of 11 to 16 µm and a carbon content greater than 0.044% unexpectedly show a lower combined of 2.8 to
5 mm

Figure 5 shows a representation of the alloys T1 to T8 and experimental melts with respect to the content of N. The alloys T1 to T8 and the experimental alloys with a grain size of 19 µm to 26 µm having all sizes of Comparable grains show a decrease in the mixture with increasing N content. Experimental alloys having a grain size of 11 to 16 µm and an N content of less than 0.010% show, as expected due to the size of grain, a bending greater than all alloys with a grain size of 19 at 26 µm. Experimental alloys with a grain size of 11 to 16 µm and a carbon content greater than 0.044%, which at the same time also have a nitrogen content greater than 0.045%, unexpectedly show a combustion equal to less than all alloys with a grain size of 19 to
26 µm.

Figure 6 shows a representation with respect to the sum of C + N. Again illustrates how C + N together reduce clearly the beaten. T1 to T8 alloys and alloys experimental with a grain size of 19 µm to 26 µm that they have all comparable grain sizes show a decrease of the combined with increasing C + N content. Alloys experimental that have a grain size of 11 to 16 µm and a C + N content less than 0.060% show, as expected due to the size of grain, a combado greater than all alloys with a grain size of 19 to 26 µm. Alloys experimental with a grain size of 11 to 16 µm and a C + N content greater than 0.09% constituted by a content of carbon greater than 0.044% and at the same time a content of Nitrogen greater than 0.045% unexpectedly show a mixture of equal to less than all alloys with a grain size of 19 at 26 µm.

A higher content of C or N also reduces the beaten so strongly that the effect is not fully compensated which increases the beating of a smaller grain size. All experimental alloys have undergone a heat treatment standard.

As Table 4b shows, sizes of Smaller grain especially with a higher C content than 0.04% In these alloys with a C content greater than 0.04% an additional reduction of the combing can be achieved by modifying standard heat treatment at temperatures slightly higher than those that later form larger grain sizes.

The V777 alloy shows the smallest combustion of All alloys It has the highest C content and one content of N in the upper third. A high content of C seems to be in especially effective consequence in the reduction of the combado.

Nickel contents below 34% worsen long service life (relative burning time), resistance specific electric and the value of ct. For this reason, 34% is the lower limit for nickel content. Nickel Contents too high cause higher costs due to the high price of nickel. For this reason, the upper limit for the content of Nickel should be 42%.

Cr contents that are too low mean that Cr concentration decreases very quickly below critical limit For this reason, 18% of Cr is the lower limit for chrome. Cr contents too high worsen the processability of the alloy. For this reason, 26% of Cr is the upper limit.

The formation of a silicon oxide layer by Under the chromium oxide layer the oxidation rate decreases. Below 1%, the silicon oxide layer is too full of holes to fully develop its action. Contents of If too high they impair the processability of the alloy. By this reason, a Si content of 2.5% is the upper limit.

A minimum content of 0.01% of La is required to obtain the action that increases oxidation resistance of La. The upper limit is 0.26%, which corresponds to a PwE of 0.38. Higher PwE values are not practical as Explain in the examples.

Al is needed to improve processability of the alloy. For this reason, a minimum content of 0.05% On the other hand, too high contents harm the processability For this reason, Al content is limited to one%.

A minimum content of 0.01% of C is required for good dimensional stability or low bending. The C is limited to 0.14% since this element reduces resistance to oxidation and processability.

A minimum content of 0.01% of N is required for good dimensional stability or low bending. The N is limited to 0.14% since this element reduces resistance to oxidation and processability.

For Mg a minimum content of 0.0005% since this process improves the processability of the material. The limit value is set at 0.05% so as not to soften the positive effect of this element.

Sulfur and boron contents should stay as low as possible since these elements Surfactants impair oxidation resistance. For this motive are set to max. 0.01% of S and max. 0.005% of B.

Copper is limited to max. 1% since this element reduces oxidation resistance.

Pb is limited to max. 0.002% since this element reduces oxidation resistance. The same applies to the Sn.

A minimum content of 0.01% of Mn is required to improve processability. Manganese is limited to 1% since This element reduces oxidation resistance.

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TABLE 2 Alloys according to ASTM B 344-83. Everybody data in% by weight

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7

8

9

10

eleven

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Claims (38)

1. Alloy of iron-nickel-chromium-silicon with, in% by weight, 34 to 42% nickel, 18 to 26% chromium, 1.0 to 2.5% silicon and additions of 0.05 to 1% of Al, 0.01 to 1% of Mn, 0.01 to 0.26% lanthanum, 0.0005 to 0.05% magnesium, 0.01 to 0.14% carbon, 0.01 to 0.14% nitrogen, max. 0.01% sulfur, max. 0.005% of B, optionally 0.0005 to 0.07% of Ca, optionally at least one of the elements Ce, Y, Zr, Hf, Ti with a content of 0.01 to 0.3%, optionally 0.001 to 0.020% of phosphorus, optionally 0.01 to 1.0% respectively of one or several of the elements Mo, W, V, Nb, Ta, Co, the rest iron and the usual impurities inherent in the procedure. 2. Alloy according to claim 1 with a Nickel content from 34 to 39%. 3. Alloy according to claim 1 with a Nickel content from 34 to 38%. 4. Alloy according to claim 1 with a nickel content from 34 to 37% nickel 5. Alloy according to claim 1 with a Nickel content from 37 to 38%. 6. Alloy according to one of claims 1 to 5 with a chromium content of 20 to 24%. 7. Alloy according to one of claims 1 to 5 with a chromium content of 21 to 24%. 8. Alloy according to one of claims 1 to 7 with a silicon content of 1.5 to 2.5%. 9. Alloy according to one of claims 1 to 7 with a silicon content of 1.0 to 1.5%. 10. Alloy according to one of claims 1 to 7 with a silicon content of 1.5 to 2.0%. 11. Alloy according to one of claims 1 to 7 with a silicon content of 1.7 to 2.5%. 12. Alloy according to one of claims 1 to 7 with a silicon content of 1.2 to 1.7%. 13. Alloy according to one of claims 1 to 7 with a silicon content of 1.7 to 2.2%. 14. Alloy according to one of claims 1 to 7 with a silicon content of 2.0 to 2.5%. 15. Alloy according to one of claims 1 to 14 with an aluminum content of 0.1 to 0.7%. 16. Alloy according to one of claims 1 to 15 with a manganese content of 0.1 to 0.7%. 17. Alloy according to one of claims 1 to 16 with a lanthanum content of 0.01 to 0.2%. 18. Alloy according to one of claims 1 to 16 with a lanthanum content of 0.02 to 0.15%. 19. Alloy according to one of claims 1 to 16 with a lanthanum content of 0.04 to 0.15%. 20. Alloy according to one of claims 1 to 19 with a nitrogen content of 0.02 to 0.10% of nitrogen. 21. Alloy according to one of claims 1 to 19 with a nitrogen content of 0.03 to 0.09%. 22. Alloy according to one of claims 1 to 21 with a carbon content of 0.04 to 0.14%. 23. Alloy according to one of claims 1 to 21 with a carbon content of 0.04 to 0.10%. 24. Alloy according to one of claims 1 to 23 with a magnesium content of 0.001 to 0.05%. 25. Alloy according to one of claims 1 to 23 with a magnesium content of 0.008 to 0.05%. 26. Alloy according to one of claims 1 to 25 with max. 0.005% sulfur and max. 0.003% of B. 27. Alloy according to one of claims 1 to 26 containing from 0.001 to 0.05% of Ca. 28. Alloy according to one of claims 1 to 26 containing 0.01 to 0.05% of Ca. 29. Alloy according to one of claims 1 to 28 with 0.01 to 0.3% respectively of one or more of the elements La, Ce, Y, Zr, Hf, Ti being the sum PwE = 1.43 \ cdot X_ {Ce} + 1.49 • X_ {La} + 2.25 • X_ {Y} + 2.19 ? X_ {Zr} + 1.12 X_ {Hf} + 4.18 \ X \ {Ti} lower or equal to 0.38, PwE corresponding to the potential of the elements assets. 30. Alloy according to one of claims 1 to 28 with 0.01 to 0.2% respectively of one or more of the elements La, Ce, Y, Zr, Hf, Ti being the sum PwE = 1.43 \ cdot X_ {Ce} + 1.49 • X_ {La} + 2.25 • X_ {Y} + 2.19 \ X \ {Zr} + 1.12 \ X_ {Hf} + 4.18 \ X_ {Ti} less than or equal to 0.36, PwE corresponding to the potential of active elements. 31. Alloy according to one of claims 1 to 28 with 0.02 to 0.15% respectively of one or more of the elements La, Ce, Y, Zr, Hf, Ti being the sum PwE = 1.43 \ cdot X_ {Ce} + 1.49 \ x X {La} + 2.25 X_ {Y} + 2.19 \ cdot X_ {Zr} + 1.12 \ X_ {Hf} + 4.18 \ X_ {Ti} lower or equal to 0.36, PwE corresponding to the potential of the elements assets. 32. Alloy according to one of claims 1 to 31 with a phosphorus content of 0.005 to 0.020%. 33. Alloy according to one of claims 1 to 32 containing 0.01 to 0.2% respectively of one or more of the elements Mo, W, V, Nb, Ta, Co. 34. Alloy according to one of claims 1 to 32 containing 0.01 to 0.06% respectively of one or more of the elements Mo, W, V, Nb, Ta, Co. 35. Alloy according to one of claims 1 to 38 in which the impurities are adjusted to contents of max. 1.0% Cu, max. 0.002% of Pb, max. 0.002% of Zn, max. 0.002% of Sn. 36. Use of the alloy according to one of the claims 1 to 35 for use in elements of electric heating 37. Use of the alloy according to one of the claims 1 to 35 for use in elements of electric heating that require high stability dimensional or a combined bass. 38. Use of the alloy according to one of the claims 1 to 35 for use in the construction of ovens